Hi,
Welcome to health care magic,
Bleeding during defection or bowel movement since long time could be due to piles,fissures, fistula or rarely any growth (cancerous) in rectum etc but I will not think above the possibility of cancer right now.
It does not necessary that his grandma had a
colon cancer then he will also develop cancer at a certain age.So,no need to be worried about it.
Felling of tearing the anus or mucosa should be examined first and then we can comment on that.
So,he must get examined by surgeon to rule out above possibilities.
He may need to undergo complete blood counts,ESR,blood electrolytes,
ultrasound of abdomen and
rectal examination to find out the actual cause.In some cases
colonoscopy will also be helpful.
Meanwhile,he may require to take quinolones antibiotics with anti-protozoals with following measures.
1) Anovate cream or ointment to be applied over anus after defecation,
2) Hot sitz bath ans sit naked in warm water for about 15 minutes
3) Avoid alcohol,
4) Avoid oily and spicy foods.
Consult surgical specialist or
proctologist who would be the best doctor to see for further evaluation.
Regards,